This week Canadian Prime Minister Justin Trudeau said he was willing to renegotiate Nafta once Mr Trump becomes president in the new year.

Mr Gingrich, when he was Speaker of the House of Representatives, raised the idea in April 1998 and it was backed by Margaret Thatcher and Right-wing Eurosceptics in Britain, but condemned by the Labour government.

Its supporters argue that a new Nafta including the UK is possible once Britain has freed itself from its obligations to the EU.